the chief foreign correspondent for nbc news, richard engel, has escaped from kidnappers in northern syria. he and his crew said they were dragged from their car on thursday by gunman supporting the assad regime. they escaped last night when their captors became engaged in a firefight with rebel forces. engel spoke in turkey today, flanked by two of his crew. we're very happy to be out. we're very happy to be back in turkey. we love being here. we love this country. we appreciate all the help. the last five days are days that we would rather forget. if you can understand, we just came out now. we haven't even left yet. we're very tired. >> holman: engel said he and his colleagues were kept bound and blindfolded, and subjected to mock executions. it was unclear whether all of the crew members escaped. five people working with a u.n. polio vaccination campaign in pakistan were shot to death today, possibly as part of a taliban campaign. a sixth worker was killed a day earlier. we have a report narrated by lindsey hilsum of independent television news. >> reporter: they were trying to p